Diaphragm type acoustic screen



May 16, 1950 R. C. JOLFRE DIAPHRAGM TYPE ACOUSTIC SCREEN Filed Dec. 10, 1947 lmi Umwhs JOEY-e,

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Patented May 16, 1950- UNITED STATES PATENT OFFICE Application December 10, 1947, Serial No. 790,766 In France January 11, 1947 1 Claim.

Employees who are constantly in contact with the public, behind windows of railway stations, of booking offices, information office windows, post-office windows, bank cashiers windows, cashiers desks of shops, and the like, are in breath to breath contact sometimes several hundreds of times per day. An employee inhales myriads of microbes and germs which are often infectious germs and necessarily contaminate anyone who is not in an immunized state. It has been observed that the morbidity of employees who are thus in contact with the public is substantially greater than that of other employees (three times greater in some cases).

The purpose of the device hereinafter described is to protect employees who are in contact with the public, from infection and contagion by the breath, while allowing the voice or sound to be transmitted so as not to hinder the exchange of conversation between the employee and the public and providing suitable rigidity and strength and also complete fluid-tightness.

According to my invention, said device essentially comprises a composite partition formed by a diaphragm such as cellophane suitably stretched on a frame, said diaphragm being enclosed between two walls of a rigid transparent substance such as plastic composition, the two walls being provided with small holes so as to allow sound waves to pass and being slightly spaced apart from the cellophane diaphragm in order to allow the same to vibrate normally. I will now describe a device according to my invention, reference being had to the accompanying drawing in which:

Fig. 1 shows a front view of a booking-oiiice window provided with a partition according to the invention;

Fig. 2 is a section of the partition.

It can be seen in Fig. 2 that the partition according to the invention comprises a cellophane diaphragm l which is transparent and is stretched on a frame 2 of suitable shape, on either side of which are equidistantly disposed plates or slabs 3, 4 of a rigid transparent and plastic material, which are provided with holes 5 of small diameter over a part or the entire surface of said slabs intended to allow sound waves to pass.

The whole arrangement is supported by a spacer frame 6 which may be integral with the frame 2 and which is intended for fixing the partition within the opening of a window.

Fig. 1 shows a window provided with such a partition. The frame 6 is fixed by means of rivets, bolts and nuts, or by other means, to a ring 7 surrounding the hole provided in the glass pane 8 of the window.

The frame is of elongated shape in the vertical direction, preferably elliptical, so that it can be directly interposed between the employee and the person standing at the window, however tall said person may be.

Tests and electrical measurements have shown that when using such a device, the loss of strength of the voice heard through this partition may be considered to be nil.

It can thus be seen that there has been provided in accordance with this invention a device for insertion in a window and like panel for protecting persons from contamination by breath Without impeding sound wave transmission and clear visibility; comprising a. composite partition adapted for position intermediate persons, said partition including a transparent cellophane diaphragm, a window frame having a central opening and engaging said diaphragm in substantially fiat condi tion at its periphery whereby said diaphragm is tautly stretched across said opening of said window frame, a box-shaped housing surrounding said window frame, said housing being defined by oppositely arranged end plates of rigid, transparent and plastic material and mounted independently of said window frame with diaphragm, and spacer means connected to said end plates and spacing the latter from said diaphragm, said end plates being provided with perforations passing through said end plates and disposed to extend over at least a part of said end plates, whereby sound waves penetrate said end plates toward said diaphragm for causing vibration of the latter within air spaces predetermined by said spacer means and said end plates.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

A device for insertion in a window and like panel for protecting persons from contamination by breath without impeding sound wave transmission and clear visibility; comprising a composite partition adapted for position intermediate persons, said partition including a transparent cellophane diaphragm, a window frame having a central opening and engaging said diaphragm in substantially flat condition at its periphery whereby said diaphragm is tautly stretched across said opening of said window frame, a box-shaped housing surrounding said window frame, said housing being defined by oppositely arranged end plates of rigid, transparent and plastic material and mounted independently of said window frame 3 4 with diaphragm, and spacer means connected to REFERENCES CITED said end plates and spacing the latter from said The following references are of record in the diaphragm, said end plates being provided with file of this patent: perforations passing through said end plates and disposed to extend over at least a part of said end 5 UNITED STATES PATENTS plates, whereby sound Waves penetrate said end Number Name Date plates toward said diaphragm for causing vibra- 2,294,912 Jurcak Sept. 8, 1942 tion of the latter within air spaces predetermined 2,310,154 Schlenker Feb. 2, 1943 by said spacer means and said end plates. 2,346,226 Marlow Apr. 11, 1944 RENE CHARLES JOLFRE. 10 

